Boundary lines are lines that mark the limits of a particular area or region. The term 'boundary lines' can be broken down into two words: 'ENDS' and 'edges'. 'ENDS' refers to the points at which the boundary line terminates, while 'edges' refers to the sides of the boundary line. Boundary lines are often used to define the boundaries of a country, state, or other geographical area. They can also be used to separate different types of land, such as public and private property.